1. Field
One or more embodiments of the present invention relate to a secondary battery.
2. Description of the Related Art
Generally, unlike a primary battery that is not rechargeable, a secondary battery is a rechargeable and dischargeable battery. Secondary batteries are typically used as an energy source of mobile equipment, electrical vehicles, hybrid vehicles, electrical bicycles, and uninterruptible power supplies. Depending on the type of external equipment to which the secondary battery is applied, the secondary battery is used in a single cell type or in a cell module in which a plurality of cells are bound to a single unit by electrically connecting the cells.
However, when an excessive current is charged or discharged in the secondary battery, high heat may be generated or an electrolyte may be decomposed. In this case, an internal pressure may be increased, and as a result, the secondary battery may ignite or explode. Therefore, there is a need to develop a structure of a secondary battery that can perform a safety operation in advance by sensing an abnormal situation, such as an overcurrent.